Re: Outlook Express No Longer Working
You don't say what version Of NAV you're running but Norton AntiVirus is just that - it scans for viruses (later versions do trojans,spyware etc as well). There is NO firewall with NAV but if you mean Norton Internet Security (or some other package with a firewall) then you should configure the firewall to allow access to Outlook Express. I expect it has blocked the program due to your install and is not in Auto configure.
The XP Firewall is generally regarded as a very poor utility and has nothing like the fire power of Norton. Like a lot of things on the computer some of these programs can be quite demanding - personally I'd get better acquainted with how Norton works and use it. Just my 5p's worth.